To provide participants in the lymphocyte biology program project with complete flow cytometry and digital imaging microscopy services. This will include sorting and analyses of immunofluorescence (up to 5 colors), for ward and narrow-angle light scatter, cell diameter (axial pulse width), membrane potential, cell cycle, and intracellular free calcium levels. Digital imaging microscopy offers the capability to analyze [Ca2+]I oscillatory behavior and subcellular localization of makers with three dimensional reconstruction.